type_decoder: silence print format warnings, greppable messages

type_decoder: silence print format warnings, greppable messages

Silence printf(3) format warnings. Python's data types should be
considered opaque, size (and signedness) are usually unknown, as is
the relation to standard C language print format specs.

Unbreak long messages which were spread across several source code
text lines. This complies to Linux style guides. Being able to find
diagnostics messages that were reported by users in sources is more
important than sticking to an arbitrary text line length.